Impulse actuated engine synchronizing mechanism



Aug. 30, 1949. K. B. BRITTON 2,480,707

IMPULSE ACTUATED ENGINE SYNCHRONIZINC! MECHANISM Filed Jan. 12, 1946 2 Sheets-Sheet 1 L INVENTOR KAPL 5. BRITTO/V A TTOR/VE) Aug. 30, 1949. BRlTToN 2,480,707

IMPULSE ACTUATED ENGINE SYNCHRONIZING MECHANISM Filed Jan. 12, 1946 2 Sheets-Sheet 2 MM 451 59/770 53/ W 3 W4 Patented Aug. 30, 1949 il'jf'i'UNITED STATES PATENT OFFICE IMPULSE ACTUATED ENGINE SYNCHBO- NIZIN G MECHANISM Karl B. Britton, Cleveland, Ohio, assignor to Bendix Aviation Corporation, corporation of Delaware South Bend, hit, a

Application January 12, 1946, Serial No. 640,940 3 Claims. (Cl. 60-4)?) invention relates to control mechanisms for a plurality of prime movers or engines, and

relates particularly to synchronizers for 'a pair of prime movers or engines.

More particularly, the invention relates to means for synchronizing and is particularly typ'e of iiuid aircraft.

It is an object of the present invention to provide anovel mechanism for synchronizing a plurality of engines.

Another object is to provide a synchronizer for a plurality of engines where the synchronizer includes novel means for transmitting and receiving impulses in accordance with engine speed.

A i'urther object comprehends a novel synchronizingmechanism which can be used in conjunction with the fluid pressure system of an aircraft.

' A yet further object is to Provide a synchronizer for a plurality of engines where a differenpressure system employed in modern tial system is employed for effecting engine synchronization without aflecting the throttle settings of said engin "Still another object is to provide an escapement device for use with an engine synchronizer whereby the speed of the synchronizer will be an at a desired minimum and at a fixed ratio with respect to engine speed.

Other objects and desirable features or the "invention will be best understood after a study of the description hereinafter following when taken with the drawings, which are for the purposeof illustration only, and which together are not to be construed as a definition of the limits of the invention, the scope and limits of the invention being determined only by the terms of the claims which are appended hereto.

In the drawings which are used for p rposes "of'illustration only:

Figure 1 is a diagrammatic showing of one of a pair of internal combustion engines, an impulse producing mechanism attached thereto, and an impulse receiving mechanism;

"j Figure 2 is a diagrammatic showing of the impulse receiver shown in Figure 1, which is connected to a throttle control through the medium of a'diiferential gear train;

"Figure 3 is an elevation view of the throttle control 'shown in Figure 2;

Figure 4 is a block diagram of the mechanism of the invention;

Figure 5 is a view in section taken on the line 5-5 of Figure 2; and

Figure 6 is a view in section of the hydraulic motor.

Referring now particularly to Figure 1, there is shown one of a pair of internal combustion engines indicated generally by the ordinal II), which produces power through the medium of a piston I2 connected by a rod M to a crank I6. The valve actuation system of the internal combustion engine l0 may include apair of timing gears IB'and 20, gear 20 being rigidly connected to the end of a cam shaft 22, upon which is mounted a cam 24 having the shape shown. As is known to those skilled in the art, the four-cycle-in-line internal combustion engine is so arranged that the crankshaft travels at twice the speed of the cam shaft, and the gears shown at It and 20 have teeth ratios accordingly.

Means are provided for furnishing an impulse in accordance with the speed of each of the enl0. As shown in Figure 1, the means comprises a rocker arm 26 pivotally mounted at 28 and having along lever arm 26a which contacts a cam 24, and a short lever arm 26b which contacts a nosepiece 30 of a hollow piston 32. The hollow piston is slidably mounted in a cylinder 36 to form a chamber 38. The chamber thus formed is in communication with a source of hydraulic fluid contained within an annular chamber 40 by means of a plurality of ports 42 contained in the wall of cylinder 36 and a plurality of ports 34 contained in the skirt of piston 32, whenever the rocker arm 26 is in contact with the root circle of the cam 24. A spring 44 contained within the hollow piston 32 tends to extend, thus keeping the nosepiece 30 and the cam 24 in firm contact with the rocker arm 26.

The chamber "is in communication with a pressure responsive device, which in this case takes the form of a sealed capsule or bellows 43, by means of a conduit 46. The sealed capsule 43 is connected by means of a. link 48 to an escapement lever 50 which is pivoted at 52. The escapement lever is equipped with a pair of cars 54 and 56 which alternately engage the teeth of a gear 58 which is driven by a hydraulic motor 60, which may be driven by pressure from any suitable source, as, ior example. the iiuldpressure system ordinarily employed in aircralt. It may be noted that at all times the motor tends to drive the escapement. The connection between the motor and the gear I! is of a type, not shown, commonly used with escapements. That is, the driving arrangement between the motor 6. and gear 58 is such as to allow the escapement lever 8| to hold the gear against rotation should the speed thereof tend to exceed engine speed.

The mechanism thus far described furnishes a means for limiting the speed of the motor II taccordance with the speed oi the engine ll. and the operation of the mechanism thus far described is as follows:

Each revolution of the cam 24 produces a pressure impulse within the chamber II and the conduit 45, thus producing alternate and cyclic elongations and contractions of the sealed bellows 43. By means of the escapement it and the linkage 48 there will be an alternate engagement by the cars it and it with the space between adjoining teeth of the gear 58. Thus, since an impulse is transmitted for each two revolutions o! the engine Ill, the ear 5 will engage every other tooth of the gear 58, and likewise the ear 5! will engage every other tooth oi the gear 50. The speed of the gear 58 will therefore be held at a fixed ratio to the speed or the engine ll.

AsshowninFigures2 and3,meansareprovided for actuating a pair of throttle controls 62 for each of the engines shown at Ill. The throttle controls 62 are slidably carried by guide 63. As shown in Figure 3, the throttle controls 82 may be actuated to bring the engine into synchronization by rotative movement of a pinion it which is'rotatably held in a master control rod 63. The master control rod it is also slidably carried by guides 61. A Bowden cable I is attached to the master control rod it to provide ior manual operation of the throttle controls 62. A given throttle setting for both engines is obtained by sliding the control rod 66 in guides 61. This sliding action or the control rod in guides 61 imparts a sliding movement to the throttle controls carried in guides 63. It will be seen, then, that synchronization of the engines It by controlling the position of the throttle 2 can be achieved by movement of the control arms of the throttle rods pinion gears I2 and II and is rotatably held in a spider l2 oi the dlfierential gear train It. The spider I! has fixedly mounted thereon a beveled pinion 84 which engages a beveled gear ll connected to the pinion N by means or a plurality of universal Joints 8! which are connected at the spline ll. The spider '2, gear ll, integral with the spider, and the pinion gear 00 all rotate as a unit about the shaft 16 to drive gear 86, when the engines are out at synchronlsm.

The operation of the system thus far described is as follows:

Each engine ll produces impulses in accordance with its speed, and the speed of each engine is reflected in the speed of its associated motor il. When the motors I are in synchronization, the

beveled pinion gear '0, which lies between the beveled pinion gears I2 and II which are driven in opposite directions, will rotate about its axis. When the two motors ill are no longer in synchronization the spider 82 will be caused to rotate, thereby transmitting rotative movement of the beveled pinion 84 and to the beveled gear 86. The rotative movement of the beveled gear 86 will, through the universal joints 8! and the splined connection 9!, effect a rotative movement to the pinion 64, which will cause the two throttle control rods to move with respect to each other. It will be seen, therefore, that one control rod 62 will cause the throttle of its associated engine ill to be opened slightly. and that the other control rod 62 will cause the throttle of its associated engine to be closed slightly, thereby bringing the two engines It back to synchronization.

Thus has been described a novel and useful improvement'in the art of synchronizing a pair of engines. While the invention has been described with reference to a particular embodiment or preferred form, it is to be distinctly understood that the invention is not limited by terms of the embodiment shown. nor otherwise than by the terms of the appended claims.

I claim:

1. A synchronizing device for a plurality of en-' gines comprising means associated with each of said engines for transmitting mechanical impulses in accordance withthe speed of its associated engine, means including a hydraulic motor associated with each engine, means including an relative to each other. Thus, it may be necessary escapement operaflvely connected t i motor to increase the speed'ot one of the e mes II to bring it up to the speed oi the other; or, it may be necessary to reduce the speed oi one engine to bring it down to that of the other. For a particular throttle setting, however, it is generally a better expedient to change the throttle positions of both engines, so that they approach the position as determined by the initial throttle setting. which is as has been described, achieved by a translative movement or the pinion 80 which is held in the rod it.

For changing the throttle position of each of the engines It to achieve synchronization, a ditierential system is employed in conjunction with the throttle control rods 62, the pinion t4, and the speed controlled motor I, one each of which is associated with each engine ll. As shown in Figure 2, the speed controlled motor ii is connected through the system of gearing associated therewith and by a flexible cable I. to a pinion I2 of a diiierential gear system It. Similarly, the fluid motor of the other engine It is connected, by a' shaft 16, to a beveled pinion gear 18 of the differential gear system ll. A beveled pinion gear lies intermediate the differential for controlling the rotation thereof, said escapement being driven by said impulses, whereby said second named means is adapted to rotate at a fixed ratio with respect to its associated engine.

55 a throttle for each engine. and means for changing the position of said throttles in accordance with the diflerence in speed between each of said engines.

2. The combination, with two engines, of a go differential gear system, a hydraulic motor for each engine having a driving connection to the diiierential gear system, means including a gear to be rotated interposed between the differential gear and motor in each of said driving connections,

as means interconnecting each of said gears to its associated engine for controlling the rotation of each gear and comprising an escapement operatlvely engaging each of said gears, a hydraulic impulse device connected to each engine, a fluid 7o bellows interposed between each escapement and its corresponding hydraulic impulse device, whereby the speed of the gear will be held at a fixed ratio of the speed of the engine. and means connected to the diflerential gear system for bringing 18 the engines into synchronization.

"3. The combination. with two engines, of a differential gear system, a hydraulic motor for each engine having a driving connection to the differential gear system, means including a gear to be rotated interposed between the difierential gear and motor in each of said driving connections, an escapement mechanism associated with each gear, means including a fluid connection between each engine and each of the escapements, whereby engine rotation produces impulses in said fluid connection to operate the escapements so that the speed of each gear will reflect a definite relationship of the speed of its corresponding engine, and means connected to the differential gear system and responsive to the difference in speeds of said gears for controlling said engines to tend to bring their speeds closer together.

' KARL B. BRITTON.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 2,087,291 Moross July 20, 1937 2,104,582 Carlson July 4, 1938 2,220,080

Crane et al Nov. 5, 1940 

